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Manta and Devil Rays (Mobulids) of the Eastern Tropical Pacific

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Manta and Devil Rays (Mobulids) of the Eastern Tropical Pacific Fact sheet for the 89th Annual Meeting of the Inter-American Tropical Tuna Commission (IATTC) Manta and Devil Rays (Mobulids) of the Eastern Tropical Pacific: Giant Manta Ray Manta birostris Chilean Devil Ray Mobula tarapacana Spinetail Devil Ray Mobula japanica Munk’s Devil Ray Mobula munkiana Bentfin Devil Ray Mobula thurstoni Proposed action: Prohibit retention and prevent harmful handling Proponent: European Union (EU) Mary O'Malley, WildAid O'Malley, Mary Overview Manta and devil ray species (family Mobulidae) are facing heavy targeted and incidental fishing pressure around the world, increasingly driven by escalating Chinese demand for their gill plates. These large, migratory rays are inherently vulnerable to overexploitation due to exceptionally low productivity and aggregating behavior. Largely unregulated fishing mortality risks the depletion of populations as well as the substantial revenue possible through tourism. Protections through the Inter-American Tropical Tuna Commission (IATTC) are warranted to preserve ecological and economic benefits, bolster existing national safeguards, and prevent long-standing depletion. Such action will also complement and fulfill obligations for these species associated with listings under the Convention on Migratory Species (CMS) and the Convention on International Trade in Endangered Species (CITES). Biology and Distribution Current Conservation Measures Mobulid rays occur in tropical, subtropical, and temperate All manta and devil rays are listed on CMS Appendix I and II, seas in fragmented, sparsely distributed populations. They which carry obligations for Parties (including Costa Rica, migrate across national boundaries, feeding on small fish Ecuador, EU, Panama, Peru) to strictly protect the species and and plankton, which they filter through pre-branchial cooperate regionally toward their conservation. CITES appendages known as gill plates. Mobulids are thought to Appendix II listings for the giant manta (and reef mantas) -- be among the world’s least fecund marine fish. Their which were proposed by Ecuador, Brazil, and Colombia, and vulnerability to overexploitation is due to late maturity (at up came into force in September 2014 – obligate Parties (including to 10 years of age), lengthy gestation (up to approximately Belize, Canada, China, Colombia, Costa Rica, Ecuador, El one year), exceptionally small number of offspring (as few Salvador, EU, France, Guatemala, Japan, Korea, Mexico, as one pup every two to three years), and long life Nicaragua, Panama, Peru, US, Vanuatu, Venezuela) to allow (estimated at 40 years for reef mantas). international trade only under permits based on findings that demonstrate the legality and sustainability of catches. Fisheries and Population Status Mobulid rays are used for human consumption and bait, Mexico, Ecuador, and the US are among the countries with taken in substantial numbers as incidental catch, and specific protections for mobulid rays. The General Fisheries increasingly sought for their gill plates, which are used to Commission for the Mediterranean is so far the only Regional make a Chinese health tonic. Demand for gill plates, which Fisheries Management Organization (RFMO) to agree can sell for hundreds of USD/kg, is driving targeted yet largely protection specific to a mobulid species (Mobula mobular). unregulated fisheries. Mobulids’ large size and tendency to move slowly in predictable aggregations can make them Expert Advice easy targets. While highly susceptible to purse seines and Family Mobulidae has been highlighted by the CITES gillnets, mobulid rays are also caught on longlines. Animals Committee as a “taxonomic group that contains Landings data and anecdotal reports indicate significant a significant proportion of species subjected to declines in mobulid populations around the world, including unregulated, unsustainable fishing pressures, leading to off Mexico and Peru. IATTC catch data (1998-2009) for severe stock depletion.” Mobula species taken in Eastern Pacific purse seine fisheries show a slow increase from 1998 to a peak in 2006 at >80t, The IATTC staff recommendations for incidentally caught followed by a subsequent steep decline, with just 40t manta and devil rays form the basis of the EU proposal. reported in 2009 (Hall & Roman, 2013). Prohibiting retention as well as gaffing, lifting by the gill slits or spiracles, and punching holes in the wings) is advised. Specific guidance for safe handling and release has also been offered. Need for Action A particularly cautious approach is warranted with respect to both the handling of individual mobulid rays and the management of fishing mortality. IATTC protections, as proposed by the EU, are urgently needed and have great potential to: Photo © Shawn HeinrichsShawn © Photo • prevent population depletion and associated negative Mobulids’ large size and tendency to move slowly in predictable effects on ecosystems and economies; aggregations can make them easy targets. • promote national conservation efforts and inspire similar action at other RFMOs; The giant manta ray is classified as Vulnerable on the IUCN • facilitate regional cooperation in protection of shared Red List. The remaining Eastern Pacific Mobula rays are populations and key habitats; currently listed in the Near Threatened or Data Deficient • enhance the potential for tourism in many island and categories based on assessments that were conducted coastal communities; and before the surge in gill plate demand. Because of concern • help fulfill commitments under CMS and CITES listings. over the exceptional vulnerability of the entire family, the IUCN Shark Specialist Group is currently working on updated We urge IATTC Parties to support the EU proposal to prohibit Red List assessments for these species as well as a retention of manta and devil rays, and ensure the use of comprehensive global strategy for mobulid ray conservation. best practices for safe, live release. Alternative Uses References The giant manta ray is a popular species for divers and Information in this fact sheet is based on the relevant IUCN snorkelers. Substantial revenue from manta-based tourism Red List Assessments (iucnredlist.org), and the following: has been documented for communities around the world, Dulvy, N., Pardo, S., Simpfendorfer, C., and Carlson, J. 2014. Diagnosing the including Ecuador, Mexico, and the US, with an estimated dangerous demography of manta rays using life history theory. PeerJ global value of 140 million USD annually. Tourist activities PrePrints 162/v1: 1-26. focused on devil rays are being developed in many places Hall, M.; Roman, M. 2013. Bycatch and non-tuna catch in the tropical tuna including the Azores, Costa Rica, Mexico, and Peru. purse seine fisheries of the world. FAO Fisheries and Aquaculture Technical Paper No. 568. Rome, FAO. 249 pp. Mobulid rays are also popular attractions for a few large, O’Malley MP, Lee-Brooks K, Medd HB (2013) The Global Economic Impact of public aquariums. Manta Ray Watching Tourism. PLoS ONE 8(5): e65051. doi:10.1371/journal.pone.0065051..
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